Cause
Only an operation whose application is queued or running can be cancelled.
What to do
Check the operation status.
application/problem+json
{
"type": "https://masnet.com/developers/errors/operation_not_cancellable",
"title": "The operation cannot be cancelled",
"status": 409,
"detail": "...",
"code": "operation_not_cancellable",
"correlation_id": "..."
}